Total joint replacement component positioning as predetermined distance from center of rotation of the joint using pinless navigation

Abstract

A system and method used in total joint arthroplasty of a ball and socket joint such as hip and shoulder replacements for accurate positioning of a prosthesis through pinless surgical navigation during replacement surgery according to a predetermined distance from the center of rotation of the replaced joint and/or articular surface to obtain the proper length, offset, and biomechanics of the replaced joint.

1 . A method of performing a total arthroplasty of a ball and socket joint of a patient using a surgical navigation system wherein the joint has a socket formed of bone and a limb formed of bone, the limb having a ball shaped head and neck at a proximal end near the socket, the method comprising the steps of:
 affixing a surgical navigation tracking sensor or marker operatively connected with a navigation processor and implant geometry database to the limb bone and/or to an implanted limb component selected from the group consisting of a broach and a prosthesis;   determining the center of rotation of the ball and socket joint relative to the navigation sensor or marker affixed to the limb bone and/or the implanted limb component; and   implanting either of a traditional stemmed limb component or a socket resurfacing limb component to a known distance from the center of rotation of the ball and socket joint.   
   
   
       2 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker to said implanted limb component such that the surgical navigation tracking sensor or marker is not attached directly to any portion of the limb bone.   
   
   
       3 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker to said implanted limb component prior to changing the anatomic relationship between the limb and socket.   
   
   
       4 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker to said limb component prior to implanting said limb component in said limb.   
   
   
       5 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker after said limb component is implanted and prior to osteotomy and removal of said head and/or neck.   
   
   
       6 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker to said implanted limb component while the head of said limb is disposed within said socket and attached to said limb using a minimally invasive surgical procedure known as the superior approach, including the step of making a superior incision for accessing said ball and socket joint.   
   
   
       7 . The method according to  claim 1 , wherein
 said step of affixing comprises affixing said surgical navigation tracking sensor or marker to said implanted limb component while the head of said limb is reduced, dislocated or subluxed from said socket and attached to said limb.   
   
   
       8 . The method according to  claim 7 , comprising the further step of:
 replacing said head back into said socket with said surgical navigation tracking sensor or marker affixed to said implanted limb component for calculating the center of rotation of said joint.   
   
   
       9 . The method according to  claim 1 , wherein
 said step of implanting said limb component comprises implanting said limb component into the proximal end of said limb while the head of said limb is reduced, dislocated or subluxed from said socket and prior to osteotomy and removal of said head and/or neck.   
   
   
       10 . The method according to  claim 1 , comprising the further steps of:
 removing said surgical navigation tracking sensor or marker from said limb component to facilitate performing an operative procedure; and   thereafter reaffixing said surgical navigation tracking sensor or marker to said limb component in the same position as before for acquiring additional accurate navigational measurements.   
   
   
       11 . The method according to  claim 1 , wherein
 said ball and socket joint is a hip joint, said socket is an acetabular socket on the pelvis, said limb is a femur having a femoral shaft and canal, said head is a femoral head adjoined to said proximal end by said neck, said implanted limb component is a femoral broach or femoral prosthesis implanted in the femoral canal, and said surgical navigation tracking sensor or marker is affixed to the implanted femoral broach or femoral prosthesis.   
   
   
       12 . The method according to  claim 1 , wherein
 said ball and socket joint is a shoulder joint having a scapula with a glenoid socket, said limb is a humerus having a humeral shaft and canal, said head is a humeral head adjoined to said proximal end, and said implanted limb component is a humeral broach or humeral prosthesis implanted in the humeral canal, and said surgical navigation tracking sensor or marker is affixed to the implanted humeral broach or humeral prosthesis.   
   
   
       13 . A method for accurately positioning a replacement prosthesis during a total hip arthroplasty of a patient's hip joint using a pinless surgical navigation procedure, the hip joint having a pelvis with an acetabular socket and a native femoral head and neck near the socket adjoined by a neck to a proximal end of a femur bone having a femoral shaft and a femoral canal, the method comprising the steps of:
 preparing the femoral canal to receive a femoral broach or femoral prosthesis component prior to osteotomy of the native femoral head and/or neck;   affixing a surgical navigation tracking sensor or marker operatively connected with a navigation processor and implant geometry database to the femoral broach or femoral prosthesis component prior to changing the anatomic relationship between the femur and socket such that the surgical navigation tracking sensor or marker is not attached directly to any portion of the femur bone;   affixing a second surgical navigation tracking sensor or marker operatively connected with the navigation processor and implant geometry database to the pelvic bone;   implanting the femoral broach or femoral prosthesis component in said femoral canal at the proximal end of the femur;   determining the center of rotation of the hip joint and utilizing the surgical navigation tracking sensor or marker and navigation processor to calculate the distance and angles between the center of rotation of the joint and a point on the femoral broach or femoral prosthesis component to ascertain the femoral offset and height needed to recreate the patient's normal anatomy;   selecting a replacement prosthesis having a femoral head and neck with size, angle, length, and anteversion corresponding to the calculated distances and angles between the femoral broach or femoral prosthesis component and the center of rotation to achieve the patient's normal anatomy; and   if the distance between the femoral broach or femoral prosthesis component and the center of rotation is outside of the range of options of the replacement femoral prosthesis, increasing or decreasing the size of the femoral broach or femoral prosthesis component and/or reshaping the femoral bone to accept the femoral component in a different position and repeating the steps of determining the center of rotation of the hip joint as needed to obtain an available correct sized replacement femoral prosthesis.   
   
   
       14 . The method according to  claim 13 , wherein
 said step of determining the center of rotation of said joint comprises rotating the femur in a circular motion and utilizing the surgical navigation tracking sensor or marker and navigation processor to calculate the center of rotation.   
   
   
       15 . The method according to  claim 13 , wherein
 said step of determining the center of rotation of said joint comprises digitally mapping the surface geometry of the femoral head utilizing a navigation probe and the navigation processor.   
   
   
       16 . The method according to  claim 13 , wherein
 said step of implanting the femoral broach or femoral prosthetic component includes inserting the femoral broach or femoral prosthetic component a known distance from the center of rotation of the hip joint.   
   
   
       17 . The method according to  claim 13 , comprising the further step of:
 adjusting the size and position of said femoral broach or femoral prosthesis component as necessary based on the calculated distance between the center of rotation and the femoral broach or femoral prosthesis component and known lengths and angles of available replacement femoral prosthetic necks.   
   
   
       18 . The method according to  claim 13 , comprising the further step of:
 determining the degrees of malrotation of the femoral broach or femoral prosthetic component by calculating the malrotation angle between the neck axis of the femoral broach or femoral prosthesis component and the neck axis of the native femoral head and neck as determined by the center of rotation of the hip joint and the center of the femoral canal.   
   
   
       19 . The method according to  claim 13 , comprising the further step of:
 determining the distance between the femoral broach or femoral prosthesis component and the articular surface of the femoral head.   
   
   
       20 . The method according to  claim 19 , comprising the further step of:
 adjusting the size and position of the femoral broach or femoral prosthesis component based on the calculated distance between the articular surface of the femoral head and the femoral prosthesis component and known lengths and angles of available replacement femoral prosthetic necks to adjust the patient's leg length and offset.   
   
   
       21 . The method according to  claim 13 , comprising the further step of:
 affixing said navigation tracking sensor or marker to the femoral broach or prosthesis to measure the distance between said surgical navigation tracking sensor or marker and a fixed reference point on the pelvis prior to osteotomy of the native femoral head and/or neck to determine a pre-operative leg length and offset measurement.   
   
   
       22 . The method according to  claim 13 , comprising the further step of:
 affixing said navigation tracking sensor or marker to the femoral broach or prosthesis to measure the distance between said surgical navigation tracking sensor or marker and a fixed reference point on the pelvis after osteotomy of the native femoral head and/or neck to determine a post-operative leg length and offset measurement.   
   
   
       23 . The method according to  claim 13 , comprising the further steps of:
 affixing a second surgical navigation tracking sensor or marker to the pelvis and determining the center of rotation of the hip joint through the first said navigational tracking sensor attached to the implanted femoral broach or femoral prosthesis component and relating that location to said second surgical navigation tracking sensor or marker attached to the pelvis.   
   
   
       24 . The method according to  claim 23 , comprising the further steps of:
 positioning the center of rotation of an acetabular reamer relative to the acetabular socket at a distance corresponding to the determined center of rotation of the hip joint;   adjusting the acetabular reamer depth and height and position relative to the center of rotation of the joint according to the calculated femoral offset and femoral height measurements and to any possible increase in femoral offset and height with different prosthetic head and neck selections; and   reaming the acetabular socket as needed to recreate the patient's normal anatomy; and attaching a navigational marker to the acetabular component during the insertion of the acetabular component to ensure the acetabular component is implanted at the proper distance from the center of rotation of the hip joint.   
   
   
       25 . The method according to  claim 13 , comprising the further steps of:
 inserting the stem of a femoral prosthesis having a modular neck stem into the femoral canal;   repeating the steps of determining the center of rotation of the hip joint to ensure that the femoral component is still at the appropriate position;   making a pre-operative navigated measurement to a reference point on the pelvic bone or a pelvic navigational tracking sensor;   cutting the femoral neck;   preparing the acetabular socket and inserting the acetabular component;   inserting trial head and neck components;   making an intra-operative navigated measurement to some location on the pelvic bone or a pelvic navigational tracking sensor; and   adjusting the trial head and neck components as necessary to achieve the desired leg length and offset.   
   
   
       26 . The method according to  claim 13 , comprising the further steps of:
 making a preoperative navigation measurement between the femoral broach and a reference point on the pelvis using navigation trackers attached to the femoral broach and to the pelvic bone;   with the femoral broach still in the femoral canal, cutting the femoral neck;   preparing the acetabular socket;   inserting an acetabular component;   attaching a trial head and neck to the femoral broach;   reducing the hip;   reattaching a navigation tracking sensor to the femoral broach and to the pelvic bone;   making a repeat measurement between the femoral broach and reference point on the pelvis; and   upon obtaining an acceptable repeat measurement in terms of leg length and offset, removing the femoral broach and inserting a correctly sized and neck angled femoral prosthesis to the same location as the femoral broach was located; or   upon obtaining an unacceptable repeat measurement in terms of leg length and offset, changing the size and/or position of the femoral component and estimating the difference in position from the initial broach and the final prosthesis, and utilizing the estimated amount of change between the two positions to achieve the desired leg length and offset.   
   
   
       27 . A method for accurately positioning a replacement prosthesis during a shoulder arthroplasty of a patient's shoulder joint using a pinless surgical navigation procedure, the shoulder joint having a scapula with a glenoid socket and a native humeral head near the glenoid socket adjoined by a neck to a proximal end of a humerus bone having a humeral shaft and a humeral canal, the method comprising the steps of:
 preparing the humeral canal to receive a humeral broach or humeral prosthesis component prior to osteotomy of the native humeral head and/or neck;   affixing a surgical navigation tracking sensor or marker to the implanted or soon to be implanted humeral broach or humeral prosthesis component prior to changing the anatomic relationship between the humerus and scapula such that the surgical navigation tracking sensor or marker is not attached directly to any portion of the humerus bone;   implanting the humeral broach or humeral prosthesis component in said humeral canal at the proximal end of the humerus;   determining the center of rotation of the shoulder joint and utilizing the surgical navigation tracking sensor or marker to calculate the distance and angles between the center of rotation of the joint and a point on the humeral broach or humeral prosthesis component to ascertain the humerus offset and height needed to recreate the patient's normal anatomy;   determining the surface geometry of the articular surface of the humeral head and utilizing the surgical navigation tracking sensor or marker attached to the humeral component to calculate the distance and angles between the articular surface of the humeral head and the humeral broach or humeral prosthesis to ascertain the prosthetic humeral head size and length needed to recreate the patient's normal anatomy;   selecting a replacement prosthesis having a humeral head size, angle, length, and anteversion corresponding to the calculated distances and angles between the humeral broach or humeral prosthesis component, the center of rotation, and articular surface of the humeral head to achieve the patient's normal anatomy; and   if the distance between the humeral broach or humeral prosthesis component, the center of rotation, and the articular surface of the humeral head is outside of the range of options of the replacement humeral prosthesis, increasing or decreasing the size of the humeral broach or humeral prosthesis component and repeating the steps of determining the center of rotation and articular surface of the shoulder joint as needed to obtain an available correct sized replacement humeral prosthesis.   
   
   
       28 . The method according to  claim 27 , wherein
 said step of determining the center of rotation of said joint comprises rotating the humerus in a circular motion and utilizing the surgical navigation tracking sensor or marker to calculate the center of rotation.   
   
   
       29 . The method according to  claim 27 , wherein
 said step of determining the articular surface of said joint comprises digitally mapping the surface geometry of the humeral head relative to the surgical navigational tracking sensor attached to the implanted humeral broach or humeral prosthesis in order to accurately size and position the prosthetic humeral head such that replaced humeral head has a similar size, shape and angle as the native humeral head.   
   
   
       30 . The method according to  claim 27 , wherein
 said step of implanting the humeral broach or humeral prosthetic component includes inserting the humeral broach or humeral prosthetic component a known distance from the center of rotation of the shoulder joint or known distance from the articular surface of the humeral head.   
   
   
       31 . The method according to  claim 30 , comprising the further step of:
 determining the angle between the neck axis of the implanted humeral broach or humeral prosthesis and the neck axis of the native humeral head and the amount of anteversion or retroversion of the humeral broach or humeral prosthesis; and   adjusting the rotation of the humeral broach or humeral prosthesis, or selecting an offset humeral head to achieve the patient's normal anatomy.